Fire equipments for liquid and gaseous fuels



Nov. 19, 1968 K. PEREDI 3,411,857

FIRE EQUIPMENTS FOR LIQUID AND GASEOUS FUELS Filed Jan. 30, 1967 4 Sheets-Sheet 1 INVENTOR. K4504 y P5250 Nov. 19, 1968 K. PEREDI 3,411,857

FIRE EQUIPMENTS FOR LIQUID AND GASEOUS FUELS Filed Jan. 30, 1967 4 Sheets-Sheet 2 4'1 3'5 3132 27 FIG.5

60b 34b 61b 30 35 33b 86b 83b 82b 60a 340 610 33a 30 860830 41 82a FIG.6

I INVENTOR. K4A 0L y fzeo/ BY JW Nov. 19, 1968 K. PEREDI 3,411,857

FIRE EQUIPMENTS FOR LIQUID AND GASEOUS FUELS Filed Jan. 30, 1967 I 4 Sheets-Sheet 5 A. 116 350' J S Y vu g L L, L an 69b- ZW/ 27b r ave-MD; {@km 45 A 45b FIG.8

IN VEN TOR.

A Amuy PEEL-"m United States Patent 3,411,857 FIRE EQUIPMENTS FOR LIQUID AND GASEOUS FUELS Karoly Perdi, Kekgolyo utca, Budapest XII, Hungary Continuation-impart of application Ser. No. 418,714,

Dec. 16, 1964. This application Jan. 30, 1967, Ser.

2 Claims. (Cl. 431-178) ABSTRACT OF THE DISCLOSURE Combination apparatus for fluid fuels, in which an elongated distribution chamber with fuel injection and an igniter at one end feeds through one or more openings to a combustion chamber which has a roof and side walls and is thus adapted to heat workpieces. Secondary air is fed directly to the combustion chamber, and the secondary air inlets may be specially arranged to spread the combustion over the combustion chamber.

The present application is a continuation-in-part of ap plication Ser. No. 418,714, filed December 16, 1964, now abandoned.

This invention relates to combustion equipment for liquid and gaseous fuels such as oil and gas.

Known combustion equipment of such type comprises either at least one reaction chamber for forming a hot gas, and a combustion chamber connected with said reaction chamber and serving for combustion of said hot gas with secondary air introduced through at least one secondary air conduit, or else it comprises a burner suitable for burning the fuel directly. The development of heat due to combustion of fuel takes place mostly immediately in front of the burner so that it is impossible to obtain desired temperatures at places where heat is to be extracted. Therefore, the known combustion equipment for liquid or gaseous fuels is, principally, suitable only for heavy-duty boilers the combustion chamber of which is substantially cooled by boiler tubes and, thus, is capable of withstanding inevitably high combustion temperatures while boilers with uncooled combustion chamber or usual industrial furnaces provided with combustion equipment of the known type such as oil burners with direct atomization of the fuel would be prematurely destroyed by hot flames, although otherwise they offer considerable technical as well as technological advantages, e.g. the possibility of adjusting the atmosphere in a furnace.

The main object of the present invention is to obviate such deficiencies and to provide combustion equipment of the described type by means of which liquid and gaseous fuels may be combusted at a uniform combustion temperature selectable within wide limits, and an atmosphere may be obtained which is adjustable independently of such temperature so as to be oxidizing, neutral or reducing even in case of boilers having uncooled combustion chambers and of industrial furnaces without destroying them.

A further object of the present invention is a quick and intensive mixing of fuel and combustion air so that combustion occurs as close as possible to the place of mixing whereby a homogeneous atmosphere is obtained. A still further object of the present invention is to obtain all types of flames such as torch flames having circular cross-sectional areas, or flat flames of various thicknesses, etc. Another object of the present invention is that the temperatures of the flame and the combustion gases respectively should likewise be selectable and adjustable within wide limits, the desired sphere of adjustment ranging from 200 to 1600 degrees centigrade. Still another object of the present invention is that the construction and working principle of the novel combustion equipment be suitable for being adjusted to various requirements imposed by lowest and highest outputs. Another object of the present invention is the prevention of coking caused by heat reflected from exceedingly hot wall-s. Still another object of the present invention is the provision of combustion equipment which is suitable for alternate or simultaneous combustion of various fuels. A further object of the present invention is the provision of combustion equipment which, although meeting all requirements referred to above, is inexpensive and capable of reliably working during a long period of time.

The invention is based on the recognition that the above-mentioned requirements can be met if combustion of the supplied fuel is delayed in a desired manner. Delay of combustion means that the development of heat is distributed in correspondence with desired places of heat withdrawal so that predetermined temperatures are obtained in the combustion chamber at desired places therein. In other words, combustion and, correspondingly, development of heat by means of primary and secondary air take place gradually, either the secondary air being mixed with the hot gas or the hot gas being mixed with the secondary air in one or more stages. The stepwise admixing requires various meeting places for the interacting media for which purpose either one of them is caused to flow in various directions to the other one from one and the same place or is supplied from various points into the combustion chamber. Thus, the hot gas has to be available prior to its encounter with secondary air and must be capable of being supplied into the combustion chamber of the combustion equipment at spatially different points. On the other hand, the secondary air has to meet the hot gas only when and where combustion of the latter is to take place.

In short, first combustion should take place in more than one stage, viz., first a combustion with primary air (first stage) and then a combustion with secondary air in at least one stage (second stage) should occur. Secondly, the media partaking in the combustion in the second stage should be supplied to one another at a predetermined point or at a plurality of points. Thirdly, secondary air should be supplied to the mixing place separately from the hot gas. All these requirements are fulfilled by the present invention which is concerned with combustion equipment for fuels such as gas and oil having, in a known manner, reaction chamber for forming a hot gas and a combustion chamber connected with said reaction chamber for burning said hot gas with secondary air, and at least one secondary air passage. In compliance with the main feature of this invention, a gas distribution chamber is provided between said reaction chamber and said combustion chamber arranged separately from said secondary air passage, said gas distribution chamber being connected through at least one gas inlet opening with said reaction chamber, and through at least one gas outlet orifice with said combustion chamber, said secondary air passage opening through at least one outlet opening directly into said combustion chamber. Thus, with combustion equipment according to the invention, complete combustion of the fuel is achieved in at least two stages: first, the oil is gasified or a heating gas is decomposed by partial combustion (first stage). Thus, a hot gas of a temperature between 600 to 1200 degrees centigrade is formed with deficient oxygen content whereafter it is burned in a second stage by means of supplying secondary air. It may happen that a complete combustion of the hot gas would entail too high temperatures even in a second stage. In order to obtain a desired low temperature at such place, secondary air will be intro duced also at a third point, the complete combustion of the fuel thus taking place in three stages. It made necessary by a desired temperature distribution, secondary air may be supplied to the hot gas at still further points in a similar manner. According to the desired nature of the combustion atmosphere, it is also possible to proceed in the reverse manner: the gas will be supplied to the secondary air as has already been described with reference to supplying secondary air to the gas.

On the other hand, the gas distribution chamber and secondary air passage according to the invention serve also for shaping the flame. By means of varying the number, form, place and direction of the gas outlet openings as well as by means of varying the size, place and number of the outlet orifices of the secondary air conduit, also the shape of the flame of the hot gas emerging from the gas distribution chamber can be considerably influenced and a desired fiat, round, fan-like or conical, etc., flame obtained.

Furthermore, combustion equipment according to the invention is suitable for being employed for several principal types of operation:

In the first type of operation, secondary air is admixed with the hot gas in two or more stages, the secondary air itself being supplied to the hot gas from the same place in the combustion chamber in various directions, or introduced into the combustion chamber at various places.

Another mode of firing is required when the temperature of the combustion gases arriving at the place of heat exchange should be lower than the combustion temperature and, moreover, than the temperature at which the hot gas is formed, and should preferably amount to about 200 to 1200 degrees centigrade as is the case with various dryers, heat-treatment furnaces and central heating boilers. Such mode of operation is obtained in that diluting media are added to the combustion gases in a separate combustion chamber whereby a desired low temperature is obtained at the place of heat withdrawal which is separated from the place of combustion. For this purpose, flue gases or air may be admixed with the combustion gases. In the case of supplying fiue gases, a reducing or neutral atmosphere is obtained whereas by employing air for dilution purposes the atmosphere is rendered oxidizing. Thus, it is possible to obtain a desired type of atmosphere independently of the temperature at which heat is withdrawn.

Further objects and details of the invention will be described with reference to the accompanying drawings which illustrate, by way of example, various embodiments thereof, and in which:

FIGURE 1 is a side cross-sectional view of a first exemplified embodiment taken along the line 1-1 of FIG. 2.

FIGURE 2 is a sectional view taken along the line II II of FIG. 1.

FIGURE 3 is a sectional view taken along the line IIIIH of FIG. 2.

FIGURE 4 shows a detail of FIG. 3 on a relatively larger scale.

FIGURE 5 is a side cross-sectional view of a further exemplified embodiment taken along the line VV of FIG. 6.

FIGURE 6 is a horizontal sectional view taken along the line VIVI of FIG. 5.

FIGURE 7 is a side cross-sectional view of still another exemplified embodiment taken along the line VII- VII of FIG. 8.

FIGURE 8 is a horizontal sectional view taken along the line VIII--VIH of FIG. 7.

FIGURE 9 is a plan view partly in section of a still further exemplified embodiment; and

FIGURE 10 is a side cross-sectional view taken along the line XX of FIG. 9.

Similar details are referred to by the same reference characters throughout the drawings, component parts or details of the same kind being referred to by reference characters complemented with letters, insofar as a plurality of such component parts or details is shown in a respective figure.

In the drawings, FIGS. 1 to 3 shown an embodiment in a boiler having an uncooled combustion chamber 30 which has a reaction chamber 31 associated with it and formed in a reaction chamber body 32. Reaction chamber 31 has an electrical ignition device 27 therein. According to whether oil is atomized by means of an atomizer, or gas is introduced by means of a nozzle, the unit 31 and 32 may be referred to as a gasifier or a decomposer, respectively.

The combustion chamber 30 may have secondary air introduced into it through conduits 33a and 33b which open each through a series of outlets 34a and 34b directly into the combustion chamber 30. The systems of conduits as referred to by reference characters 33a and 33b, and outlets as designated by 34a and 34b, will be referred to by the term secondary air passages.

Now, in compliance with the main feature of the invention, a gas distribution chamber 35 is provided between the reaction chamber 31 and the combustion chamber 30, arranged separately from said secondary air passages 33a, 34a, 33b, 34b and connected with the reaction chamber 3.1 through a gas inlet opening 38. At its other extremity, the gas distribution chamber 35 is connected with the combustion chamber 30 through gas outlet orifices 36. The mean cross-sectional area of the gas distribution chamber 35 preferably amounts to about the triple to quintuple value of the smallest cross-sectional area of the reaction chamber 31.

The combustion chamber 30, the reaction chamber 31 and the gas distribution chamber 35 are, in the illustrated embodiment, located in a wall 41, the reaction chamber 31 having increasing cross-sectional area toward the gas distribution chamber 35 which is accessible through a manhole 42 for inspection. A lid 43 serves for closing the manhole 42.

The atomizer 29 is preferably built as shown in FIG. 4. Oil is introduced into the atomizer 29 through an oil pipe 45 and becomes atomized by pressure air or steam introcluced through a conduit 39. The atomized oil flows from the atomizers 29 through an outlet nozzle 40 into the reaction chamber 31.

In order to obtain atomization without coking, the outlet nozzle 40 will have a cone angle of at most 12 and preferably of 6 to 8.

Through a conduit 46 provided with an adjusting means such as a slide valve 47 there flows primary air to a burner head 37 whence it enters the reaction chamber 31. In a similar manner a conduit 48 serves for introducing poor gas or any necessary diluting agent, such as flue gases, the introduced amount of which can likewise be adjusted by means of an adjusting means 49. A like arrangement for atomizing oil may be provided at the top as regards FIG. 2.

The secondary air conduits 33a and 33b are supplied with secondary air through conduits 50a and 5011, respectively. The free cross-sectional areas of such conduits may be regulated by adjusting means 51a and 51b. The conduits 50a and 50b are connected with their associated secondary air conduits 33a and 33b through ducts 52a and 521;, respectively. Boxes 44a and 44b serve for connecting the ducts 52a and 52b with the conduits 50a and 50b, respectively.

As will be seen particularly in FIG. 1, the outlets 34a and 34b of the secondary air conduits 33a and 33b, respectively, are partly oriented in difierent directions in that the axial lines of the outlet openings 34a enclose a smaller angle a with the vertical central plane of the equipment and the combustion chamber 30, respectively, than the central lines of the outlets 34b of an angle of inclination 3.

Similar equipment for supplying secondary air (not shown) being arranged at the other side of the vertical axial plane IIIIII as well, the axial lines of the outlets 34a and 34b, respectively, intersect with the axial lines of their associated symmetrically arranged opposite outlets for secondary air in the axial plane III-III of thecombustion chamber 30. Accordingly, amounts of second ary air introduced through the outlets 34a and through those on the opposite side become mixed with the gas introduced through the outlet orifices 36 into the combustion chamber at a higher level and at a greater distance (at an angle 0:) than secondary air amounts which enter through the outlets 34b and their associated outlets at the other side of the vertical axial plane IIIIII of the combustion chamber 30 (at an angle ,8). This is readily understandable by considering the arrows 60, 61a and 62a in FIG. 1.

In operation, oil flows in the direction of arrow 66 through the atomizer 29 and becomes atomized by an atomizing medium supplied through the conduit 39 in the direction of arrow 65. The primary air fiows in the direction of arrow 67 through the conduit 46 and the adjusting means 47 into the burner head 37 and thence into the reaction chamber 31. The atomized mixture of oil and air entering the reaction chamber 31 is ignited by the ignition device 27 and gasified, the combustible hot gas flowing into the gas distribution chamber (arrow 68). Thence the hot gas flows through the outlet orifices 36 in direction of the already-mentioned arrow 60 into the combustion chamber 30.

Meanwhile, secondary air flows in amounts adjusted by the adjusting means 51a and 5117 through the conduits 50a and 50b and the ducts 52a and 52b into the secondary air conduits 33a and 33b, respectively, whence it flows, on the one hand, through the outlets 34a in direction of arrow 62a and, on the other hand, through the outlets 34b in direction of arrow 61a into the combustion chamber 30 (FIG. 1). Here, first the secondary air entering in the direction of arrow 61a through the outlets 34b is admixed with the hot gas introduced in the direction of arrow 60. In accordance with the introduced amount of secondary air as adjusted by the adjusting means 51b, one portion of the gas will then be burnt whereas a still combustible other portion thereof remains unburnt. This portion, in a further stage as it were, fiowing in the direction of arrow 60 contacts the secondary air introduced in the direction of arrow 62a in the upper portion of the combustion chamber 30. Thus, vertically of the latter, combustion is delayed so that thermal overload of the furnace wall is avoidable since by heat extraction in the upper portion of the combustion chamber 30 and delaying the combustion in the lower portion thereof only moderate temperatures will prevail.

It may be desirable that the mixture of oil and air has also another gas (e.g. flue gases for the purpose of diluting) admixed with it in the atomizer 37. Thus, also a lean gas, for instance blast furnace gas, may be used by being rendered more concentrated by means of atomized oil or decomposed rich gas, e.g. methane. Then, such gas (arrow 64) will be introduced through conduit 48, in amounts adjusted by the adjusting means 49, into the burner head 37 and the reaction chamber 31.

FIGS. 5 and 6 show an enameling furnace having combustion equipment according to the invention. As is known, ovens of such type are, in the case of direct oil heating, exposed to excessively high temperatures and, consequently, to premature damage even if refractory bricks of finest quality are used. On the other hand, an enameling furnace provided with combustion equipment according to the invention is suitable to be operated at a.uniform and moderate temperature so that heat loads of the refractory wall decrease considerably with respect to known furnaces of similar type, while their lifetime markedly increases.

The gas distribution chamber 35 is located centrally beneath an enameling furnace (not shown). The combustion chamber 30 lies partly beneath and partly at both sides of the furnace. Secondary air flows through secondary air conduits 33a and 33b which are formed in the walls'of the furnace and the outlets 34a and 34b of which are, in the represented embodiment, somewhat contracted in the flow direction 61a and 61b of secondary air. Thus, it is possible to measure the inner pressure prevailing in the outer conduits a and 50b of the secondary air (that is, of the secondary air in the second stage) between the adjusting means 51a and 51b and the furnace body 41, and to adjust the flow condltlons by the former in dependence on the measurements obtained.

In the embodiment of FIGS. 5 and 6, the furnace is provided also with conduits 82a and 82b for supplying tertiary air (that is, secondary air in the second stage) which open through ducts 83a and 83b in the dlrection of arrows 86a and 86b into the combustion chamber 30 as is evident from FIG. 5

Gas emerging from the gas distribution chamber 35 meets amounts of secondary air arriving through the outlets 34a and 34b, and becomes partly combusted (first stage). Meanwhile, the combustion products flow along the left-hand extremity of the furnace 1n the dlrection of arrows a and 60b upward and reach the lower portion of the combustion chamber 30 whence they flow in the direction of arrow 84 toward the right-hand extremity of the furnace (FIG. 5) where they start to fiow upward in direction of arrow 85 agaln. The combustion gases meet here tertiary air emerging from the ducts 83a and 83b in the direction of arrows 86a and 86b, respectively, so that complete combustion takes place (second stage) and combustion gases flowing 1n the directlon of arrow 87 at the left-hand extremity of the furnace no longer contain any combustible components.

Thus, in the illustrated embodiment, the hot gas 1s burned in two stages (the oil in three stages) 1n that first primary air for the purpose of gasificatlon, then secondary air in the direction of arrows 61a and 61b, and finally tertiary air in the direction of arrows 86a and 86b are supplied. However, it is also possible to burn the hot gas in more than two stages if such combustion is desired, obtain a still lower temperature and a more uniform temperature distribution in a relatively longer furnace.

The above-described embodiment of combustion equipment according to the invention is suitable also for use with more intricate retorts than shown, such as tunnel kilns consisting of retorts that continuously operate and for obtaining a uniform temperature throughout.

FIGS. 7 and 8 show a tunnel kiln having oil gas or rich gas firing. This embodiment is characterized in that gas distribution chambers 35a and 35b are provided at both sides of the tunnel kiln. Secondary air flows 1n the combustion chamber (kiln chamber) 30 in the direction of arrows 69a and 69b (FIG. 8) under the action of an exhauster or fan (not shown) at the end of the kiln. A carriage 72 is arranged for running on rails 73a and 73b in the tunnel kiln and is moved in the direction of the arrow 76 opposite to the directions 69a and 69b of the secondary air. Thus, on the one hand, a new workpiece 74 is preheated by the exiting combustion gases while, on the other hand, the secondary air is preheated by a discharged workpiece 74 which, in turn, is cooled down. Thus, the amount of heat taken up by workpiece 74 when entering the kiln is practically recovered upon leaving it. The gas introduced into the combustion chamber 30 through gas inlet orifices 36a and 36b provided in more than one row and meeting the secondary air in a plurality of stages forms a soft flame suitable for heat treatment and burning of sensitive workpieces such as insulating or ceramic materials. In addition to delaying the combustion, a prescribed maximum value of temperature will be adjusted by correspondingly adjusting the flow rate of oil and the velocity of movement of the carriage 72.

FIGS. 9 and 10 illustrate an embodiment of combustion equipment according to the invention for use as an il burner for a boiler of a central heating system having C t iron portions. As is known, oil must not be directly burnt in the combustion chamber of such boilers wherein the temperature of the heat-carrying medium must not exceed a maximum value of e.g. 1150 C.

In the illustrated embodiment, a gas distribution chamber 35 of oblong shape with burner heads 36a and 36b at both extremities thereof is provided beneath a combustion chamber 30. The gas distribution chamber 35 opens through gas outlet orifices 36 into the combustion chamber 30. Conduits 33a and 33b serve for admitting secondary air supplied at a rate which sufiices for a complete combustion of the fuel. Conduits 33c and 33d, likewise arranged separately from the gas distribution chamber 35, open directly into the combustion chamber 30. However, they serve for admitting diluting agents such as air or flue gases the amount of which is adjusted according to a thermometer 91 at the top of the boiler. Both the secondary air and the diluting air or the flue gases are introduced through a number of small outlets, as designated by reference characters 34a and 34b, so that short flames and uniform dilution are obtained.

The upper portion of the combustion chamber 30 is connected through flue gas conduits 92a, 92b, 920 with heat-transmitting devices 93a, 93b, 93c respectively, of known type, the heat transmission taking place between the combustion gases and water which circulates in the cast-iron members of the central heating system (not shown). Flue gas conduits 94a, 94b, 94c serve for discharging the combustion gases into a common oiftake or chimney flue (not shown).

Such an embodiment of the invention can be used not only for boilers of central heating ssytems but also for dryers and heat-treatment furnaces, and more particularly for replacing electrically operated apparatus of such installations.

Thecombustion proper of the hot gas takes place according to the above-mentioned mode of operation wherein combustion and heat exchange take place separately from one another.

As is clear from the above-described several illustrated embodiments, by employing combustion equipment according to the invention, it is made possible to meet even the requirements of consumers who are faced with the most severe combustion conditions and the most delicate operations. It makes possible the use of heating oils in such installations as smaller industrial furnaces, boilers of giant power stations and, particularly, industrial furnaces which have heretofore been unable to burn oil.

It is also obvious that combustion equipment according to the invention permits obtaining temperatures Within wide limits of e.g. 300 to 1700 degrees centigrade and atmospheres of any desired type (reducing, neutral, oxidizing) merely by suitable employment of the gas distribution chamber and suitable arrangement of the secondary air passage. While with the known combustion equipment with burners, the value and place of a desired temperature as well as the nature of the resulting atmosphere are determined by the type of the burner, with the invention-due to the burners being dispensed with and due to employing the gas distribution chamber according to the inventionboth the value and the plac of a desired temperature and the nature of the atmosphere are capable of being selected independently of one another.

The following claims refer to oxygen, which is to say oxygen in any form, whether as air, or as oxygenenriched air, or as relatively pure oxygen, or as oxygen in any other form or admixture.

Having described my invention, I claim:

1. Combustion apparatus for fluid fuels, comprising a distribution chamber, means for supplying fluid fuel to the distribution chamber with less than enough oxygen to complete the combustion of the fuel in the distribution chamber, means for igniting the fuel-oxygen mixture in the distribution chamber, a combustion chamber communicating with the distribution chamber through at least one opening, and means defining inlets for supplying secondary oxygen directly to the combustion chamber, there being a plurality of secondary oxygen inlets into the combustion chamber spaced apart generally transverse to the direction of burning fuel through the combustion chamber, the secondary oxygen inlets being disposed at acute angles that converge with the direction of flow of the burning fuel through the combustion chamber.

2. Combustion apparatus as claimed in claim 1, the secondary oxygen inlets farthest from the path of the burning fuel being disposed at the smallest said acute angles.

References Cited UNITED STATES PATENTS 2,840,361 6/1958 Hermans 263-8 3,124,193 3/1964 Klein 158-53 790,863 5/1905 Anderson 158*7 3,254,695 6/ 1966 Brodlin 1584 3,255,802 6/ 1966 Browning 158-4 FOREIGN PATENTS 494,154 5/1919 France.

FREDERICK L. MATTESON, 111., Primary Examiner.

E. G. FAVORS, Assistant Examiner. 

